How do I validate the format of a MAC address?

Question

What\'s the best way to validate that an MAC address entered by the user?

The format is HH:HH:HH:HH:HH:HH, where each H is a hexadecimal ch

Answer 1

private static final String MAC_PATTERN = "^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$";

private boolean validateMAC(final String mac){          
          Pattern pattern = Pattern.compile(MAC_PATTERN);
          Matcher matcher = pattern.matcher(mac);
          return matcher.matches();             
    }

Answer 2

#Just works Perfect
#validate the MAC addr

#!/usr/bin/python
import re

mac = "01-3e-4f-ee-23-af"

result = re.match(r"([0-9a-fA-F]{2}[-:]){5}[0-9a-fA-F]{2}$",mac)

if result:
    print ("Correct MAC")
else:
    print ("Incorrect MAC")

Answer 3

If you want to ensure that there is either '-' or ':' throughout but not both, you can use following in Python:

import re

def is_valid_macaddr802(value):
    allowed = re.compile(r"""
                         (
                             ^([0-9A-F]{2}[-]){5}([0-9A-F]{2})$
                            |^([0-9A-F]{2}[:]){5}([0-9A-F]{2})$
                         )
                         """,
                         re.VERBOSE|re.IGNORECASE)

    if allowed.match(value) is None:
        return False
    else:
        return True

Answer 4

Dash-separated MAC addresses can also contain a '01-' prefix, which specifies it is an Ethernet MAC address (not token ring, for example ... who uses token ring?).

Here's something that is somewhat complete and easy to read in a logical step-through way:

def IsMac(S):
  digits = S.split(':')
  if len(digits) == 1:
    digits = S.split('-')
    if len(digits) == 7:
      if digits[0] != '01':
        return False
      digits.pop(0)
  if len(digits) != 6:
    return False
  for digit in digits:
    if len(digit) != 2:
      return False
    try:
      int(digit, 16)
    except ValueError:
      return False
  return True


for test in ('01-07-09-07-b4-ff-a7',  # True
                '07:09:07:b4:ff:a7',  # True
                '07-09-07-b4-GG-a7',  # False
                 '7-9-7-b4-F-a7',     # False
                 '7-9-7-b4-0xF-a7'):  # False
  print test, IsMac(test)

Answer 5

This Regex validates the following MAC format

"Ae:Bd:00:00:00:00"
"00-00-00-00-00-00"
"aaaa.bbbb.cccc"

private static final String MAC_PATTERN = "(([0-9A-Fa-f]{2}[-:.]){5}[0-9A-Fa-f]{2})|(([0-9A-Fa-f]{4}\\.){2}[0-9A-Fa-f]{4})";

public class MacRegExp {

    private static final String MAC_PATTERN = "(([0-9A-Fa-f]{2}[-:.]){5}[0-9A-Fa-f]{2})|(([0-9A-Fa-f]{4}\\.){2}[0-9A-Fa-f]{4})";

    static boolean validateMAC(final String mac){          
        Pattern pattern = Pattern.compile(MAC_PATTERN);
        Matcher matcher = pattern.matcher(mac);
        return matcher.matches();             
    }

}

Hope this helps